The species was published to science in 1985 in the International Aroid Society journal Aroideana, volume 8, #3, pages 73 to 79.   Found in the tropical west African rain forests of Gabon, Uganda, Cameroon, Equatorial Guinea, Zaire, Benin, Nigeria, and Angola,  Internet sites sometimes claim Cercestis mirabilis is also found in Kenya but no scientific evidence to support that claim can be found. 

Cercestis mirabilis is a member of the larger plant family Araceae and members of this family are commonly known as aroids.  The scientific name Cercestis in common Latin is pronounced  "ser-SES-tes" while mirabilis is pronounced "mir-AB-ilis".

Cercestis mirabilis was formerly known scientifically by a variety of scientific names including Nephthytis picturata, Rhektophyllum congense, and Rhektophyllum mirabile but all those are now synonyms of the accepted species name Cercestis mirabilis.  A synonym is a previously published name applied to a species that has already been published and is correct as to genus placement.  In this case the species was incorrectly placed twice in the wrong genera so the originally published names became invalid.

Originally placed in the genus Rhektophyllum that genus is no longer scientifically applicable to this species.  The genus Rhektophyllum has been distinguished from the genus Cercestis since the later has perforated leaf blades in the adult leaf forms.  Please be aware most of the color photos on this page are all of juvenile to sub-adult specimens with the exception of Dr. Josef Bogner's black and white and color photos which were taken in Gabon, Africa.  Some were originally printed in the International  Aroid Society journal Aroideana.  None of the color photos other than Dr. Bogner's show the perforations and or slits since they don't develop until the plant begins to produce mature blades.  At the bottom of this page you will find a series of photos showing the progression of the morphogenesis of this species from juvenile to adult.

While working on the genera Rhektophyllum in 1973 German aroid botanist Dr. Josef Bogner found it necessary to move the species from the genus Rhektophyllum N.E. Br. to the genus Cercestis Schott.   The change was required due to specific characteristics of the species which did not fit the originally published description of the genus Rhektophyllum.

The population of the species in the wild is quite dense in regions where it is common.  Cercestis mirabilis is frequently observed creeping up tree trunks and has been found climbing in the African rain forest to a height of 7 to 15 meters (20 to 50 feet). The epiphytic (epi-FIT-ic) tree climbing species has long roots which hang to the ground from branches high on the host tree.  Cercestis mirabilis also grows in soil and the wild the species is known as being hemiepiphytic.  A hemiepiphyte (hemi-EPI-fit) is a plant that begins life as a seed dropped on the soil which proceeds to climb any neighboring tree

Like almost all aroids as a specimen matures it morphs into a plant with a totally different color and shape!  The colors begin to slightly turn yellowish and the attractive pattern fades  as the speciemen ages.  The pattern on the leaves is known as being maculate which simply means "blemished".  Eventually the pattern fades significantly as the blades become substantially larger and less attractive.

The adult leaf blades of the genus Cercestis have holes or divisions that may be open from the midrib to the leaf margin (edge) and appear somewhat like some of the members of the more commonly collected subfamily Monsteroideae (Rhaphidophora, Epipremnum, etc.) often found in Asia.  The juvenile leaves of both known Rhektophyllum species do not posses these holes and are both entire and variable in their forms.  The adult blades of Cercestis mirabilis divide to the midrib and take on rather odd shapes as can be seen in Josef's photos.

The blades of Rhektophyllum species range from from ovate (oval) to cordate-hastate (heart to spear shaped with the basal lobes pointing outward at right angles). The basal lobes are the two uppermost lobes on any leaf.

All the known species of the genus Cercestis have ovate lanceolate (oval and lance shaped)cordate (heart shaped), sagittate (arrow shaped), hastate (spear shaped) or trilobate (triple lobed) leaf blades in the adult stages. 

It is important to understand there are no adult leaf blades seen on this page other than those seen in Dr. Bogner's photographs.  The leaves of Cercestis mirabilis are glabrous which indicates they are smooth and lack any hairs or bristles.  In young plants or shoots the leaf blades are not perforated but as the blades enter the adult growth stage the perforations begin to form.

The white areas (maculate) of a juvenile Cercestis mirabilis are puffed and raised above the darker green areas.  The plant appears to have been placed in an embossing machine and stamped which is why it sometimes called the African Embossed Aroid.   You can both see and feel the raised areas.  Even more amazing is the juvenile blades of Cercestis mirabilis appear to have another plant carefully painted on it's leaves since the youngest leaves are both dark green and variegated with patterns found between the primary veins resembling a fern's fronds.

In adult plants the leaves are semi-glossy and possess the slit-like perforations which are located between the primary leaf veins on each side of the midrib.  Adult leaves are solely green and possess none of the variegation collectors have come to expect in this species.  Older blades always split into segments.  The adult blades of Cercestis mirabilis are subcoriaceous to coriaceous and can range in length up to 1.2 meters (47 inches) long by 1 meter (39 inches) wide.   Coriaceous indicates the blades are leather-like while sub-coriaceous indicates just less than leathery to the touch.

In adult leaves of C. mirabilis the forelobe at the top of the blade is ovate or oblong-ovate while the basal lobes are broadly rhombic-ovate (oval with somewhat the shape of a parallelogram) or even somewhat hatchet shaped.  The forelobes may also be obtuse (possessing rounded or blunt tips) with a broad sinus found between the the two lobes.

Within aroids and other plant species the veins on a leaf have specific names. The prominent veins on Cercestis mirabilis are the midrib, basal ribs, primary lateral leaf veins and interprimary or secondary veins. The minor veins are known as the tertiary veins.  (see photo below, right)

Cercestis mirabilis possesses 3 to 4 primary lateral veins on each side of the midrib which is the rigid central support vein that runs from the top to the bottom of each leaf.  The primaries are relatively rigid.  At the top of the blade can be observed basal veins sometimes called the basal nerve with 2 to 4 branches. The veins are only slightly sunken on the upper surface (adaxial blade surface) but on the lower surface (abaxial surface) are paler in color. The major veins are very distinct as well as raised on the blade's underside while the secondary (interprimary) veins are raised but still less distinctive.

Despite the tendency of the majority of collectors to call the support for each leaf blade a "stem" scientifically the stalks that support the leaves are correctly known as petioles.  A petiole connects the leaf lamina of any blade to the stem which is at the base of the plant.  The stem is the central axis and support for the plant and supplies water and nutrients to all parts of the plant as it is collected by the roots.  A major purpose of the stem is to store water during periods of dry weather.  The stem is not the primary support for any leaf. Please read this link for a more detailed explanation.

The petioles of Cercestis mirabilis may grow to as long as .23 meters (.75 feet) to up to 1.37 meters (4.5 feet) long in an adult plant. The petioles are terete (round) and are grooved at the base when the plant is in the adult stage.

Along the stem can be found internodes which are the segments found between two nodes. The petioles which support the leaf blades as well as the roots grow from these nodes.  In the case of Cercestis mirabilis the internodes are short leaving the nodes closely spaced together. The stem of a fully adult plant may grow to 2.54 cm (one inch) in thickness while producing very adhesive roots from the nodes.  The roots clasp any supporting tree.  The nodes are typically well rooted.The stem may produce leafless runners in order for the plant to reproduce asexually.  Although most collectors will be tempted to call the runners "stolons" they are correctly known to science as flagellas.  The flagellas can grow quite long and periodically produce new juvenile plants as they come in contact with soil.  If you cut the small plants from the flagella too soon they will not survive. They must begin to develop their own root system before being removed.  Several of our small plants have found the soil on their own and are now beginning to develop as new specimens capable of surviving on their own. 

Cercestis species are members of the larger plant family Araceae (uh-RAY-see ee) commonly known as aroids. An aroid is characterized by the growth of an inflorescence which is the sexual reproductive organ of the plant.  We regret we have never observed the inflorescence of this species and know of no source for a photograph.

The major parts of an inflorescence are the spathe and spadix. If you have ever seen a "Peace lily" you've seen an inflorescence. That species which is a member of the aroid genus Spathiphyllum produces inflorescences on a regular basis but despite everyone calling the spathes "flowers" they aren't flowers at all.  Instead a spathe is more like a "flower holder".   When an aroid is referred to as "flowering" the reference is to the very small flowers which are produced along the spadix and has nothing to do with the spathe itself.  Despite the spathe being called a "flower" on many websites it is not a flower. The only connection between the spathe and the flowers on the spadix is both spathe and true flowers are produced when the plant is sexually active.  The spathe is simply a modified leaf which forms in the shape of a hood. The spadix is located at the center of the spathe and is a spike on a thickened fleshy axis.

Flowers contain near microscopic sexual parts including anthers, stamens, and stigmas during the reproductive process and a spathe contains none of these sexual characteristics. The inflorescence contains the tiny reproductive organs of the plant and once the inflorescence enters sexual anthesis the spadix produces tiny flowers which can be observed with a good magnifying glass. Those flowers include male, sterile male and female flowers. Once an insect collects the pollen produced by the male flowers from another plant of the same species and brings it to a second plant the female flowers may be pollinated.

The inflorescence of Cercestis mirabilis grows from the stem on a stalk-like support known as the peduncles. There are often two to four inflorescences produced together when the plant is preparing for sexual reproduction during sexual anthesis. The spathe is normally just over 10 cm (4 inches) long and is green to pale yellow in color.  The spadix is stout as well as shorter than the spathe.  The spadix grows between 2.55 and 5 cm (1 to 2 inches) long and grows to 1.25 cm (.5 inches) in thickness.  The male portion of spadix where the male flowers grow is a creamy yellow while the female portions are pinkish.  Once the inflorescence is pollinated by an appropriate insect the berries produced will be pink-red to red in color and contain the seeds of the species.  You can read about pollination in aroid species here. 
Natural pollination in aroid species.

Botanists have theorized the method used by  C. mirabilis' to fool animals that might otherwise eat it for lunch is to make them believe they are about to eat something distasteful.   That "painted" plant resembles a fern and ferns are frequently left uneaten.  The scientific theory is the plant protects itself by mimicking a plant that is less appealing to grazing animals.

We give the plant subdued light with approximately 60% shade along with frequent watering and high humidity maintained above 85% at all times. During the summer we keep it damp but in the winter allow it to slightly dry.  We have plant in a mixture of good potting soil, peat, Perlite, orchid bark. finely sliced sphagnum moss and cedar mulch with a good helping of crushed volcanic rock. This mixture drains quickly while holding enough moisture in the soil.   The mix we use is based on the mixture used by many of the world's top botanical gardens.

Cercestis mirabilis is a slow grower and the species is widely variable.  The natural variation within Cercestis mirabilis can be observed by reviewing all the photos on this page but is even more apparent when a fully adult blade is available. Variation within aroid species is very common and this link provides a non-technical explanation of both variation and morphogenesis (ontogeny) within aroid and other plant species.  Natural variation

 

Our original specimen was acquired as a trade from Windy Aubrey in Hawaii.

Aroid Pollination!   As it occurs in nature and by any horticulturist

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All Photographs not otherwise credited
© 2007, 2008, 2009 Steve Lucas, The Exotic Rainforest